Talking machine for recording and reproduction



Sept. 1, 1936. w RABALD 2,053,108

TALKING MACHINE FOR RECORDING AND REPRODUCTION Filed March 5-, 1934 v 2 Sheets-Sheet 1 Sept. 1, 1936. w; RABALD 2,053,108

TALKING MACHINE FOR RECORDING AND REPRODUCTION Filed March 3, 1934 2 Sheets-Sheet 2 Patented Sept. 1, 1936 eater orator TALKING MACHINE FOR RECGRDDIG AND REPRODUTION Willy Rabald, Leipzig, Germany Application March 3, 1934, Serial No. 713,835 In Germany March 1, 1933 8 Claims. (01. 274-2) This invention is intended to serve for the realization of the handiest apparatus for recording spoken letters and other sounds.

Such an apparatus must meet the following 5 requirements:--It must be always ready for use at any time and at any place, it must be small and easy to operate, avoid almost all secondary noises both of the record and also of the gearing and must be cheap to use. The sound records must be capable of recording as much matter as possible and allow the full utilization oi the surface of the record and interruption of the recording at any moment by quick stopping and starting.

The invention relates to atalking machine for recording and reproducing, which takes all these requirements fully into consideration. Owing to its properties it is suitable for all kinds of ofiices, for authors, reporters and for private use, in fact for everyone. it can further be advantageously employed in schools ior teaching foreign languages and elocution.

The problem of a record letter writer-is thus solved, because the tedious writing either by hand or on the typewriter is eliminated, the record sent through the post in arr-ordinary envelope not onlyimparts to the recipient the thoughts of the sender but also the individual intonation and manner of speaking. In the case of blind persons the tedious feeling of the blind characters is no longer necessary as the blind can hear the messages, purport of written articles, books and the like. I

The talking machine for recording and repro- 35 ducing sound according to the invention, therefore represents. an important advance in a cultural and economical sense.

By employing a novel record from which sounds can be reproduced as often as desired, a good 40 reproduction of sound with very little secondary noise is ensured and, owing to the small size of the record, a low selling price is possible.

It is not desirable, according to the invention,

. for the record to give a loud sound reproduction 45 as otherwise strangers could also hear, consequently the large lateral tone deflections, such as are generally employed on the known records, are not necessary. This enables a much more compact cutting of the sound grooves and consequently a greater capacity of the record.

For producing a sound record the apparatus is gripped with one hand, a starter is actuated 'with the index finger and then the speaking or singing is commenced, the apparatus being held near the mouth. The record can be directly re- ,produced. The reproduction or strength of the sound corresponds approximately to that of a telephone.

The endeavours hitherto made in this direction have not yet succeeded in. producing a result 5 similar-to that obtained by the invention. The known apparatus and devices only fulfill the requirements to a limited extent, they are incorrvenient, difiicult to manipulate and transport and, what is most important, very expensive.

The operation of the talking machine according to the invention corresponds to a miniature talking machine of known type generally known in a much larger construction under the name Gramophones but which enables both record- 15 ing and reproduction and can'be accommodated in a boxlike casing in so-called waistcoat pocket size.

The obtaining of a pure sound reproduction, as free as possible from secondary noises, pre- 29 sents great difiiculties owing to the lack of a flywheel for compensating the irregular movement of the driving mechanism, such as is formed by a large and consequently heavy record turntable.

It has been endeavoured to overcome this objection by constructing the governor at the same time as a ilyweight. This method requires an absolutely smooth driving transmission to the turntable, because all, even the slightest shocks, 30 have a very disagreeable efiect when listening to a record, owing to the vibration of the sounds. The necessary transmission is attained by employing inner wormwheel-teeth made of material causing no noises. By employing such inner wormwheel teeth a compact construction with high ratio of transmission is obtained, a smooth and uniform rotation of the turntable being effected by the connection with the governor and especially by the fact that several teeth are in mesh.

An embodiment of the invention is illustrated by way of example in the accompanying drawings'in which Fig. 1 shows in elevation natural size.

Fig. 2 is a side elevation of Fig. 1.

Fig. 3,shows the casing with lid opened and with the diaphragm housing.

' Fig. 4 is ai1"elevation showing the rear side of 59 the mechanism carrying the record plate.

Fig. 5 is a section on line C D of Fig. 3.

Fig. 6 is a section on line A -B of Fig. 3.

Fig. 7 is asection on line E-'F of Fig. 6.

Fig. 8 shows a section through the diaphragm the outer casing in.

22 with a needle 6|.

casing, turned through an angle of 90 relative to toothed wheel 6 is arranged which transmits the rotary movements to the transmission wheels 6, l, 8, 9 and In, the toothed wheel l meshing with a toothed segment II for the purpose hereinafter described. ,The toothed wheels 2'and 6-||l are arranged in theorder described on the underside of a plate |2 'flxed by screws on the lower casing half. l3. This casing half I 3 is connected in known manner withthe upper similarly shaped casing half by means of a hinge|5 and carries the other parts in such a manner that, after the removal of the screws holding the plate |2,'this plate can beitaken out of the casing with all the parts arranged above and below it.

A record turntable I6 is provided above the plate l2-for carrying a record "of special construction; the plate l2 also carries a diaphragmhousing It provided with a sound aperture I9. This housing is of circular shape and has in its under side an aperture 20 for accommodating the diaphragm 2| gripped at its edge between resilient intermediate .layers and a needle holder The diaphragm housing I8 is mounted by means of a fork-shaped extension 23, in a bracket 24 fixed on the plate l2 and can move easily between points 25.

Therecord turntable l6 has an upwardly projecting socket 26 having at its lower end a toothed wheel 21 with helical teeth, and is rotatably mounted on a pin 28. The pin 28 is situated eccentrically to the central axis of the plate l2, this eccentric arrangement, rendered necessary by the governor drive hereinafter described, also gives access to the spring driving mechanism.

Atoothed rim 29 provided with inwardly directed helical teeth is provided for the governor drive on the under side of the turntable l6.

The turntable I6 is driven by the toothed wheel- .21 owing to the fact that thiswheel meshes with a toothed wheel 3| arranged onthe under side of this plate l2 and carries a toothed wheel 32 which meshes with the toothed rim 4 on the upper spring barrel plate 3. The toothed wheel 32 cooperates with. a pawl 65 provided on the toothed wheel 3 I and forms a locking device for the winding of the spring. A box-shaped'casing 33 extends from the under side of the plate I 2 and this casing has on its inner side a concentrically arranged sleeve 34 which serves for directly guiding an axle 35 together with the bearing sleeve '36 for the governor drive. 40 with a plurality of centrifugal elements 33 (in the example illustrated ,flve) uniformly distributed around its circumference. The centrifugal elements 39 are held by accurately straightened blade springs 44.

The circumference of the spring barrel bottom 31 is formed by a channel 4| openin downward direction, the outer wall 42 of this channel 4|, having a damping surface 43 for example a velvet lining, restricts the outward deflection of the centrifugalelements 39' and maintains constant the rotation of the governor. By thus building the governor a compact construction is attained.

This axle 35 carries a disc A toothed wheel 50 is fixed on the upper end of the axle 35 and meshes with the internal teeth 30 of the toothed rim 29.

The driving spring *5 is connected at its outer end, which participates inthe'rotation, to a pin 45 projecting from the inner wall of the spring barrel 38 and at its other 'end by means of a pin 46 to a block 41 which can be coupled with the plate .|2 or with the sleeve 34 situated on its under side.

The coupling which must evidently take place before the fixing of the plate l2 by screws, is

effected by means of a bayonet joint (Fig. 11) the sleeve 41 having a slot 48 the vertical portion .f ofwhich is-open at its lower end and adapted to "receive the inwardly extended pin 46 fixed in the block 41, whereupon the sleeve is turned. In this manner the position of the inner end of the spring is held unchangeable, and the spring barrel 38 with all the parts connected and coordinated thereto are protected against dropping out.

To enable the rotation of the record turntable Hi to be started and stopped as desired the following device (starter) is provided (Figs. 4 and 6). A rack 52 projecting from the casing part l3 and terminating at its outer end in a knob 5| is mounted on the under side of the plate l2. This rack 52 meshes with a pinion 53 and is continually pressed outwards by a spring 54. The pinion 53 carries a brake strip 55 bent to correspond to the rest of the arrangement. When the knob 54 is depressed together with the rack 52 this rack causes a part revolution .of the pinion so that the brake strip 55 swings outwards and during this movement shifts thegovernor disc 40, thereby bringing the governor almost directly to the necessary speed of rotation by the sliding off a reinforced point on the outer side of the bottom' from the rack 5|) this latter jumps back under the action of the spring 54 and rotates the pinion 53 in the opposite direction, whereby the brake strip returns into its initial position and immediately stops the drive. The bracket 24 carrying the diaphragm housing I8 is pivotally mounted in the plate I2 by means of a pin 56 with a boxshaped sleeve .51, so that its toothed segment pressed on to the sleeve 51 imparts a part rotation to the bracket 24 and also-to the diaphragm housing l8, when the driving mechanism is engaged.

The gearing 2 and 6 to ID respectively imparts the swing to the toothed segment II in a predetermined ratio to the speed of rotation of the record turntable I6, the extreme positions of the toothed segment coinciding with the commencement and end of the record grooves. Moreover the path of the toothed segment II is limited by a lever 59 which contacts on the one hand by a pin 63 and on the other hand with the edge of the turntable l6.

During the making of a record the engaged lever 53 forms a rigid connection with the bracket 24 and the toothed segment whereas during the reproduction and when the lever 59 is disengaged the diaphragm housing It is followed by the needle 6| sliding in the record groove.

In order to ensure, during the making of a record, an absolutely reliable following of the record H on the turntable l6 and prevent anyshifting owing to the deflection of the needle 6| during the making of the record, an eccentrically mounted pin 60 is provided beside the pin 26 of the turntable l6 and by hearing against the flank of a suitably shaped, approximately pear-shaped 'can be made of the fulcrum oi the needle holder 22 is arranged so that a low constructional height is possible with a gear ratio, for example 1:2. A screw 62 easily accessible from the outer side, serves for securing the needle 6| in the needle holder 22 which must be. made very compact construction.

For producing the sound grooves in the record during the making of the record, sharp cuttin'g needles are employed which are unchangeable in position (shaped needle shank which protects it against turning) whereas for sound reproduction needles made of soft material are used.

Owing to the fact that the talking employed almost exclusively in vertical position for the purpose of easy manipulationyit is necessary iorthe diaphragm housing It to press the needle against the record with the necessary pressure (inscribing pressure). For this purpose a spring G5 is provided in the extension 23 of the membrane housing l8.- When closing the casing cover it a nose 61 therein presses against the upwardly projecting spring end which'is held in position by anotch 1. A pocket size apparatus for recording and reproducing sound records, comprising in combination a casing composed of an upper part having a central aperture and alower'part hing-' edly connected to the upper part, a' turntable eccentrically mounted in the lower part of said casing, a spring motor beldw said turntable comprising a spring, and a spring barrel with a toothed rim with outwardly directed helical teeth, a rim on the under side of said turnhelical teeth, a

table with inwardly directed tram ofgears engaging both rims to transmit the movemen of said toothed from said spring barrel to said turntable, a sleeve rigidly c0nnected to the underside of said turntable and extending through said spr'ng barrel, a governor disc on the lower/end of saidbarrel concentric with said turntable, centrifugal elements on the periphery of said disc, an inverted channel forming the periphery of said spring bridging the periphery of said governordisc, the inner. surface of adapted to restrict the outward movement of said elements to regulate the speed of rotation of said a I turntable, a forked bracket pivotally mounted on said driving motor outside the peripheryoi said turntable, a diaphragm bracket, a diaphragm resiliently mounted in said short owing to the machine is with said train of gears. 1 t

as specified in claim 1 rack, a pinion meshing barrel and j the outer wall of said channel housing mounted on said I diaphragm, a needle detachably mounted. in said holder, and means actuated by said motor for swinging said bracket to swing said needle irom the centre towards the periphery of said turntable.

2. In an apparatus as specified in claim 1 the means for swinging said bracket, comprising a 3 housing, a needle holder on the underside of said train-oi gears driven by the spring barrel, and'afl,

toothed segment rigidly connected to-said bracket and meshing with saidtrain oi gears.

3-, In an apparatus as specified 'in claim 1 means ior detachably coupling the spring to the turntable, comprising a plate rigidlymounted on the brake.

5. In a pocket size apparatus as specified in.

claim 1 the means for swinging said bracket, comprising a'train of gears driven by the spring barrel, and a toothed segme'nt rigidly connected to said bracket and meshing with said train of gears, a lever' carriedby said bracket to swing the same andbring said toothed segment into engagement 6. In an apparatus means for stopping and tor, comprising a press starting the spring moknob provided with a rotated bysaid rack, a brake strip rigidly con nected with said pinion and normally bearing against the regulator disc, said brake strip adapted to be swung off said regulator disc at the depression of said kno '7. In an apparatus as specified in claim 1 two inwardly projecting points 'on the bracket, an extension projecting radially from the diaphragm housing and engaged by saidpoints to allow said housing to be swung towards and away from the plane of the turntable, a spring in said extension, a nose fixed on the inner side of said lid and having a notch adapted to'receive said spring to lock the two casing parts in closed position and press said needle against the record on said turntable. I

81 In an apparatus as specifiedin claim 1 the turntable having a central pin and an eccentric pin and the record having a pear-shaped aperwith and adapted to be ture adapted to receive both of said pins to prewrin Ran in- 

